The invention relates to a method for regulating the lateral guides of a metal strip, particularly in rolling plants, for example, in the entry or exit of roll stands or in front of driving apparatus, or also in other strip processing lines.
Methods for regulating the lateral guides of a metal strip, are already known from the prior art. Such guides usually consist of two rulers arranged laterally of the path of the strip which are positioned by means of hydraulic cylinders and can be pressed against the strip and adjusted relative to the strip as the strip travels through. The known systems frequently have a mechanical coupling of both rulers as well as a common regulation for their adjustment. While such systems are relatively easy to conceptionalize, their adjustment possibilities, and particularly their regulation, are very limited. Not all strip patterns can be corrected sufficiently. Damage to the metal strips and the rulers cannot always be sufficiently avoided.
Moreover, methods are known in which, during the guidance of a strip, one ruler is operated in a position-regulated manner, while the other ruler is pressed with a defined force against the strip. The determination of the pressing force between the ruler and strip is, in this method, carried out for both sides. During the guidance of the strip, the ruler is held on one side in a position-regulated manner at a fixed position. The other ruler is pressed in a force-regulated manner with a defined force against the strip. The desired force of the force-regulated ruler is fixedly preset in dependence on properties of the strip to be guided, such as material, width, thickness, temperature or speed. This desired force is selected in such a way that it is always greater than the contact force of the strip on the force-regulated side because otherwise, the guide on this side could be opened by the strip. A disadvantage of this method is the fact that when the strip exerts a force against the position-regulated side, the reaction force and additionally the preset force on the force-regulated side, must be absorbed. Damage to the strip and also to the rulers is the result. Consequently, for the repair of the rulers long idle times of the plant are unavoidable. In addition, another disadvantage of this method results from the fact that the width of the strip to be guided is generally not constant. By presetting a fixed desired force independently of the width of the strip to be guided, the rulers cannot be adequately adjusted to different strip width patterns, so that at best, the guidance is inadequate or such high forces occur between strip and rulers that significant damage occurs.
The Laid Open Application DE 4003717 A1 discloses another method for the lateral guidance of a rolled strip. It is the object of the disclosed method to increase the service life of the guide rulers in a roller conveyor. For this purpose, a regulation of the guide rulers is proposed which operates in such a way that it alternatingly can be pressed against the edges of the strip, and then can be lifted off from the edges. Among others, this method has the disadvantage that the desired values for a force-regulated loop are preset by a process computer in accordance with an input, and the regulation can, in many cases, not take place with sufficient accuracy. Because of the preset desired forces, this method also has the above-mentioned disadvantage that this method still causes fast unsatisfactory wear, and additionally, significant strip edge damage may occur.
The publication DE 698 29 454 T2 discloses a method for regulating the lateral guidance of a metal strip.
The technical object, which results from the prior art, is consequently to be seen to make available an improved regulating method for lateral guides of metal strip, or at least to avoid the above-mentioned disadvantages.